Pump-control mechanism



May 3, 1927. 1,627,376

R. CONRADER PUMP CONTROL MECHANISM Filed June 26. 1924 3 Sheets-Sheet 1 Q9... J j m N w 4| B K M A? W m m m MN Q R w v R w 1,627,376 y 1927- R. CONRADER PUMP CONTROL MECHANI SM Filed June 26, 1924 3 Sheets-Sheet 2 Patented May 3, 1927.

UNITED STATES RUDOLPH CONRADEB, F

ERIE, PENNSYLVANIA.

PUMP-CONTROL MECHANISM.

Application filed June 26,

This invention is designed to provide an automatic control for pumps, particularly air pumps, or compressors,'driven'by electric motors. \Vith such pumps it is desirable when the discharge or receiver pressure reaches a certain. maximum due to a discontinuance of ause of air to automati cally shut down the compressor and again to automatically start the'compressor when the pressure reaches a predetermined min mum. If an. alternating motor is used th s starting not only involves-the throwing of the ordinary switch but also involves a control which first throws the switch to starting position and after the motor reaches the desired speed throws the switch to a running position. This has heretofore been accomplished by electric means which are expensive and mom or less complicated. With the present invention the controlling switch is actuated by pumped fluid, or air and thus can be made-very much more economically and is more rugged in use. ,It is also de-' sirable to unload the compressor at starting and in the present invention this is '-accom plished,. the compressor being automatically:

loaded after the motor is at speed and this may be accomplished, if desired, with a plural unit:compressor and as exemplified the apparatus is so arranged. These form the subjectmatter of the present invention together with such features and details as are expressed in the following specification and claims. 7

The, invention is illustrated in the accompanying drawings as ollows:z r

Fig. 1 shows a side elevation of a, compressor.

Fig. 2 an elevation, partly in section, of the controlling devices.

Fig. 3 a plan view of the ressure storage chamber and immediate mec anism.

Fig. 4 a section on the line 44 in Fig.3. Fig. 5a sectional view of the primary controlling pilot valve.

Fig. 6 a sectional view of the secondary controlling pilot valve. 7 s

1 marks the compressor cylinder, 2 its bed, 3 its drive shaft, 4 the drive 'wheel on the drive shaft, 5 an'electric motor dr'iving the the compressor, 11 and 12 discharge valves controlling the discharge passages 9 and 10,

1924. Serial No. 722,594.

and 13 a' partitionv between the discharge passages so that one side of the compressor may be unloaded leaving the other side in operation, thus making a two unitcompressor, i

"The compressor discharges to a receiver'= 14 from the passage9 through the rimary unloadsr 15, and through the secon ary 'un'- loader 16 from the passage 10. The un-.

loader. 16has a body 17, a discharge valve 18 held to its seat 20 by a spring 19, and an unloader' valve 21 operating on a seat 22 leading to a discharge opening 23.= A cylinder 24 isaxially arranged relatively to the valve 21. A plunger 25 is'arranged in the cylinder and connected by a stem 26 with the valve .21. The stem extends through a guide bar 27 and a spring 28 arranged on the stem tends to close the valve 21, the unloader being in a. general way similar to the unloader shown in my application Serial Number 583,798, filed August 23,- 1922. The'unloader is operatedin a manner hereinafter described. The unloader 15 is exactly similar to the unloader ,16. -It has the parts 18? to 28' corresponding to the parts 19 to 28 of theunloader 16. The unloader 15 is connected by a pipe" 29 with the receiver and controlled by a pilot valve 30.

The pilot, valve 30 is in its general construction similar to a pilot valve shown and described. in my application, Serial Number 678,368, filed Dec. 3rd, 1923.' It

.has the inlet fitting 31 oonnected to the pipe 29 and the fitting 31is secured to a body- 32. A cylinder 33 is secured in-the bodyand has ports 34 and '35 leading to a discharge passage36. A piston 37 operates'in the cylinder. A push pin 38 extendsthrough an I opening 39 in a head 40 in theend of the body and enga es a lever 41 pivotally mounted on the dy and-provided with a cross head 42, the cross head being adjustably mounted on the level. by means, of a screw 43. Springs 44 extend from the cross head to an anchor pin '45 on the body and resist the movement of'the piston. When 'the pressure in the receiver reaches its predetermined max mum this acting on the piston moves the piston over uncovering the ports 34 and permitting an inflow of air to the unloader and unloading the left side of the compressor, the opposite side of the compresser continuing to operate. A starting switch 46 has the usualstarting arm 47.;

These switches are of ordinary commercial broken from an construction and ordinarily have a neutral position of the arm, a starting position at one side of the neutral position and a running position at the opposite side of the neutral position. In Fig. 2 the starting arm is shown in the running position, the neutral position being approximately horizontal. The starting arm is pivoted on a rod 48 and has atrip arm 49. The trip arm is adapted to be caught by a latch 50 mounted on a pin 51-50 that when the arm is pulled down to der in the manner hereinafter described the latch is tripped,-thus permitting the arm to' be thrown to neutral and stop the motor.

The latch is alsodesigned to be tripped by electric means, the latch having a rearwardly extend'ing arm 50. A spring 50" tends to swing the latch upwardly to release thestartingar'm and a solenoid 50 in a shunt circuit with the suppl wires operates to pull the latch down. TVhen thecircuit is cause the solenoid releases the arm 50' an the'spring pulls the latch upwardly, releasing the starting arm.

The starting arm is connected to a controlling rod 55 through a pin and slot connection 56. The rod 55 extends to a piston 57, the rod having a head 58 which extends into a socket 59- in the piston. The head is cushioned in both directions'by a spring 60 so as to obviate shock on the starting arm through a rapid action of the piston.

Springs 61 are arranged at each side of the piston and, tend to move the piston to the neutral position and with' it the starting arm' to neutral position. The piston .is

mounted'in a cylinder 62 and the cylinder has the exhaust ports 62 which are uncovered with the piston in the lowermost or running position as shown in Fig.2.

A pilot valve 63 is similar to the pilot valve 30, having parts 31 to 45 similar to the parts'described in connection with the pilot valve 30, except that the opening39 is larger than the opening 39 S9 as to form an exhaust passage. The inlet'31 of the pilot valve 63 is connected by a pipe 64 directly with the receiver 14. The pilot valve has its'discharge passage 36 controlled byfa check valve 65 and leads to a 'fluid pressure storage chamber 66, the purpose of which is to store fluid under pressure with which the motor may be started afterthe mo or is shut downwhen the receiver pressure reache its final maximum limit. A passage 67 is connected with the discharge passage 36" of the pilot valve 63 and leads by way of a pipe 68 to the trip cylinder 54 heretofore described so that when the receiver pressure reaches a pressure to operate the pilot valve 70 63 the movement of the piston 37 uncovers. the port 34 and through the channels just described operates the latch 50 and releases the starting arm 47 so as to permit the switch to swing to neutral position to stop the motor.

At the same time the pilot valve 63 delivers air to the trip device italso delivers air through the check valve to the storage chamber 66. storage chamber to the cylinder 24 of theunloader 16 and immediately unloads the unloader 16. The unloader 16 operates at a slightly higher pressure than the unloader 15 so that in the ordinary running of the the channels described stops the motor and at the same time unloads the compressor, the purpose of which is to prepare the compressor for a re-starting operation.

A pipe 70 leads from the storage chamber to an opening 71 in the body of the pilot valve 30 and is connected with an annular passage 72 in the head 40 and with ports 73 leading to the cylinder 33. Ordinarily thisun'loader would be unloaded at the time the chamber 66 was charged but if there has been any sticking or failure of the movement of the piston air moves through the pipe 70 by way of the openings referred to and the ports 35 to the unloader 15' and consequently assuring the unloading of the This also is desirprimary unit unloader. able if the pilot valves are set. to have a wide variation, in the opening and closing of the same. This is accomplished in the pilot valves 30 by the cams 46 and 47* on the lever 41 whichoperates with relationto conforming cams on a lever 48" pivoted at 49. The resistance-of the lever 48" may be varied by a spring 50 arranged in a nut 51" in the manner of the pilot valve in' the application above referredto. The pilot valve 63 has similar mechanism marked 46 to 51 respectively. The effect of this mechanism is that the lever operating on the cams resists the movement of the main pilot valve lever until the maximum pressure is reached, then through the cam action retarding a'returnmovement'sothat there is quite a wide drop in receiver pressure, or actuating pressure,

before the pilot valve returns to its former 3 'A' pipe 69 leads from the 80 \Vhen the supply drawn from the 90 position. If this were set in a. wide range of the pilot valve 63 it might be that the unloaders 15 would load up prior to the re starting of the compressor and the connection through the pipe makes sure that the unloader 15 will be unloaded at the starting position whether as against any sticking or failure of the pilot valve, or as a Inisadpist ment of the retarding devices on the pilot valves. A pipe 74 18 connected with the pipe 68 and leads to a valve cylinder 75. A piston 76 is arranged in this cylinder and carries a valve 77 which is adapted to control a passage 78 leading to the pressure cylinder 66. A spring 79 tends to open this valve. It will be noted that when the pilot valve is operated and air is turned into the pipe 68 it is led to the upper end of the cylinder and immediately shuts the valve 79 preventing an escape of air from the storage chamber 66. The piston 76 has a vent passage 80 which is brou ht into register with a port 81 in the cy inder 75 when the piston 76 is in its lower position. The purpose of this is to vent through a pipe 82 and valve mechanism the lower end of the cylinder 62 and prevent the formation of a vacuum resistin the upward movement of the piston 57. he pipe 82 is connected with an opening 83 in a second vent controlling valve arranged in a cylinder 84. A plug valve 85 is arranged in the cylinder 84 and has an annular port 86 which is adapted to connect the opening 83 with an opening 87 leading by a pi e88 to an opening 89 in the lower end 0 the cylinder 62, thus completing the connection heretofore described for venting the cylinder and this completes the closing down of the motor and the unloading of the compressor when the maximum pressure is reached and this leaves the starting arm in the neutral position.

To automatically re-start the motor the following movements take place: When the receiver pressure has fallen to a position to permit the piston 37 of the pilot valve 63 to return to its original position this exhausts through the passage 39* and ports 35 the air from the passage 67*. This immediately takes the pressure 01f the trip piston 53 and permits it to return to its normal position and it also takes the pressure oil the top of the piston 76 permitting the opening of the valve 77 by means of the spring 79. Air under pressure'then moves from the storage chamber 66 through the pipe 82 and through the passages heretofore described to the bottom of the cylinder 62 and acting on the bottom of the piston 57 moves it to the uppermost position carrying the starting arm 47 to the upper, or starting position. This starts the motor. Both unloaders, however, remain in unloading osition through the pressure delivered to t m by way of the storage chamber 66.

I prefer to hold the switch in starting p0 sition until the motor has reached a predetermined speed and this is accomplished in the present structure in the following manner: A speed sensitive device is provided with a centrifugal head 90. This is mounted on a shaft 91 carried. in a bearing 92 arranged at the upper end of the storage chamher. A belt 93 extends from the motor to a pulley 94 arranged on the head. Arms 95 are mounted on the head and weights 96 are pivotally mounted at 97 on the arms 95. The weights have the bell crank arms 98 which operate against a pin 100 extending through the shaft 91. The pin 100 engages a lever 101. A spring 102 operates against the lever and draws the same toward the right against the centrifugal action of the \ve1ghts,'thus forming the centripetal element of the control device. The lever 101 is pivoted at 103 and its lower end engages a head 105 arranged on a valve stem 106. The valve stem has a valve head 107 which controls a. valve opening 108. A spring 109 tends to close the valve and ports 110 connect the valve with the storage chamber. The passage 108 is connected with an opening 111 and this is connected by a pipe 112 with the upper end of the cylinder 84. \Vhen the motor reaches the desired speed the centrifugal force of the weights overcoming the spring, operates on the lever 101, opens the valve 107 and air then moves by way of the pipe 112 to an opening 113 in the upper end of the cylinder 84, pushing down the plug valve 85 and uncovering a port 114 in the cylinder 84, thus putting the openings 113 and 114 in communication and air is delivered by way of the opening 114 through a pipe 115 to the upper end of the cylinder 62. The same downward movement of the plug valve brings the port 86 past an exhaust port 83, thus breaking the communication between the ports 83 and 87 and establishing communication between the ports 87 and 83, thus venting the lower end of the cylinder 62 and permitting the free and immediate downward movement of the piston. This downward movement of the piston immediately brings the starting arm 47 to the running position of the motor andthe compressor is then in full 0 oration, and the latch 50 is dropped into the position shown in Fig. 2 locking the arm 47 in this downward, or running osition.

Immediately when the piston 57 reaches its lower position, it uncovers the exhaust ports 62 which lead directly to the atmos phere and inasmuch as this is through the pipe 115, ports 114, 113 and pipe 112 communicating at this point with the pressure chamber by way of the valve 107 the pressure chamber is immediately discharged of all pressure and this immediately operates the unloader 16 to load one end or unit of the compressor regardless of receiver pressure and also operates the unloader to unload the opposite end or unit of the compressor providing the receiver pressure is above that set for the unloader 15in other words, withdraws the influence of the pressure communicated through the pipe 70. The parts now continue to run in their normal pumping operation, the unloader 15 unloading and loading so long as it will control the compressor and the final operation of stopping the compressor taking place only when this method of control will not suflice.

In order that the piston 57 may readily move upwardly when tripped I prefer to vent the upper end of the cylinder. It will be noted that when the pressure on the top of the valve 85 is released by way of the ports 62 the valve 85 immediately moves upwardly through the influence of a spring 85 so that the full communication between the ports 113 and 114 is closed. I prefer to provide a small vent 113 in the valve 85 between these ports so as to readily vent the upper end of the cylinder. When the pressure goes on the storage chamber and the valve 107 is closed at the same time the compressor stops and the spring 102 retracts the lever and permits the valve 107 to close. This opens a vent 116 so that when the device again starts there is a vent for the upper end of the cylinder permitting the piston 57 to rise to the starting position when the cycle of operation heretofore described takes place.

Summarizing the operation, it will be seen that in the ordinary operation of the compressor the unloader 15 Will be loaded and unloaded oil and on as the pressure require ments approximate the full capacity of the compressor. lVhen, however, the capacity of the compressor pumping only one unit,

I or one end, is more than that required for the supply, the receiver pressure finally builds up so as to operate the pilot valve 63 and this delivering air through the pipe (38 operates the trip piston 53 and trips the latch permitting the starting lever to swing back to the neutral position and thus stop the motor. The pilot valve 63 at the same time it operates delivers air to the top of the cylinder on the piston 76 closing the valve 77. The stoppage of the motor also relieves the centrifugal force operating against the spring 102 and this spring withdraws the leverlOl permitting the valve 107 to close. The opening of the pilot valve (53 not only delivers air to the pipe 68 but also to the storage chamber 66 which receives the full receiver pressure. The air is delivered through the pipe 69 actuating the unloader -16 and through the pipe 70 insuring the unloading by the unloader 15 so that both ends of the compressor may run light at starting. Under this condition the piston 57 is at the neutral position and the starting arm is at the neutral position. There is a fully charged storage chamber 66 of full receiver pressure and this condition continues to exist until a sufficient supply has been drawn from the receiver to reduce its pressure to a point at which the lever 48 will be overcome by the cam 47 as well as the spring 44". When this happens the pilot valve 63 is reversed and this immediately exhausts the air from the trip cylinder 54 and the top of the cylinder 75, thus'openin the valve 77. \Vith the opening of the va ve 77 air is delivered by way of the pipe 82, port 86, and pipe88 to the lower end of the cylinder 62, thus forcing the piston immediately to its upper or starting position, the air in the upper end of the cylinder venting by way of the vent 113 and the vent 116. As soon as the motor is fully to speed its action on the speed responsive device moves the lever 101 and opens the valve 107. This puts the chamber 66 in communication through the pipe 112 with the top of the cylinder 84, thus forcing downwardly the plug valve and delivering air directly on to the top of the piston 57 and forcing it downwardly to its running position. .As it reaches its running position it is locked in this position by the latch 50 and also as it reaches this position the. cylinder 62 is exhausted through the ports 62. The lower end of the cylinder is vented by wayof the pipe 88 and the port 84 during the downward movement of the piston. With the parts in this condition the motor is fully'in operation and as the pressure is removed from the chamber 66 the unloader 16 loads up and the unloader 15 may unload depending on the receiver pressure operating through the pipe 29.

While I have shown this as a plural unit compressor with two units it will be understood that it is not limited to two units and while I have shown the device as applied to a discharge unloader it will be understood that the device is not limited to unloaders operating at the discharge.

What I claim as newisz- 1. In a pump control mechanism, the combination of a pump; an electric motor actuating the pump; a starting switch having a starting and a running position at opposite sides of a neutral position; and fluid actuated means responsive to conditions of fluid pressure subjected to the action of the pump actuating switch.

2. In a pump control mechanism, the combination of a pump; an electric motor actuating the pump; a starting switch having a starting and a running position at opposite sides of a neutral position; and a fluid actuated means responsive to conditions of fluid pressure subjected to the action of the pump actuating the switch adapted to automaticall start and stop the motor in response to aid pressure conditions.

3. In a pump control mechanism, the combination of a pump; an electric motor actuating the pump; a starting switch having a starting and a running position at opposite sides of a neutral position; and means actuated by the pump fluid actuating the switch. 7

4. In a pump control mechanism, the combination of a pump; an electric motor; a starting switch comprising actuating mechanism having a starting and a running position at opposite s'des of a neutral position; a trip device holding the switch in running position; and fluid actuated means responsive to pressure conditions of the fluid and subjected to the action of the pump moving the mechanism to starting and running positionsmnd actuating the trip device.

5. In a pump control mechanism, the combination of a pump; an electric motor; a Starting switch comprising actuating mechanism having a starting and a running position at opposite sides of a neutral position; a trip device holding the switch in running position; fluid actuated means responsive to pressure conditions of the fluid and subjected to the action of the pump moving the mechanism to starting and running positions and actuating the trip device; and an electric device responsive to current conditions acting on the trip device,

6. In a pump control mechanism, the combination of a pump;an electric motor actuating the pump; a starting switch comprising actuating mechanism having a starting and a running position at opposite sides of a neutral position; fluid actuated means responsive to pressure conditions of fluid subjected to the action of the pump actuating the switch; and a speed responsive device controlling the timing of the transfer oi the switch from starting to running position.

7. In a pump control mechanism, the combination of a pump; an electric motor actuat'ng the pump; a starting switch comprising actuating mechanism having a starting and a running position at opposite sides of a neutral position; means'actuated by the pumped fluid actuating the switch; and a speed responsive device controlling the timing of the transfer of the mechanism from starting to running position.

8 In a pump control mechanism, the combination of a pump; an electric motor; a staiding switch comprising actuating mechanism having a starting and a running position at opposite sides of a neutral position: a trip device holding the switch in running position; fluid actuated means responsive to pressure conditions of the fluid and subjected to the action of the pump moving the mechanism to starting and running positions and actuating the trip device; and a speed responsive device controlling the moment of the transfer of the mechanism from starting to running position.

9. In a pump control mechanism, the combination of a pump; an electric motor actuating the pump; a starting switch having a starting and a running position at opposite sides of a neutral pos tion; fluid actuated means responsive to pressure conditions of fluid subjected to the action of the pump actuating the switch adapted to automaticall start and stop the motor in response to tiiiid conditions; an unloader; and mechanism coacting with said means maintaining the unloader in unloading position as the motor is started.

10. In a pump control mechanism, the combination of a pump; an electric motor actuating the pump; a starting switch having a starting and a running position at opposite sides of a neutral position; fluid actuated means responsive to conditions of fluid pressure subjected to the action of the pump actuating the switch adapted to automatically start and stop the motor in response to fluid conditions; a speed responsive device controlling the timing of the transfer of the switch from starting to running position; an unloader; and mechanism coacting with said means and device maintaining the unloader in unloading position as the motor starts.-

11. In a pump control mechanism, the combination of a pump; an electric motor actuating the pump; a starting switch having a starting and a running position at opposite sides of a neutral position; means actuated by the pumped fluid actuating the switch; a speed responsive device controlling the timing of the transfer of the switch from starting to running position; an unloader; and mechanism coacting with said means and device maintaining the unloader in unloading position as the motor starts. a

12. In a pump control mechanism, the combination of a pump having a plurality oi pumping chambers; an electric motor driving the pump; an unloader for one chamber operating to unload and load its chamber in response to variations of fluid conditions; a starting switch having a starting and a running position at opposite sides of a neutral position; and means responsive to other variations in fluid conditions actuating said switch. I

13. In a pump control mechanism, the combination of a pump having a pluiality of pumping chambers; an electric motor driving the pump; separate unloaders for the chambers operating in response to different pump controlled fluid conditions, one unloading and loading its chamber with the motor in motion in response to variations in conditions; and means unloading all chambers as the motor is started.

14. In a pump control mechanism, the combination of a pump having a plurality of pumping chambers; an electric motor drivin the pump; a starting switch for the motor Ixaving a starting and a running position at opposite sides of a neutral position; separate unloaders for the chambers operating in response to different pump controlled fluid pressure conditions, one unloader unloading and loading its chamber with the motor in motion'in response to variations in fluid pressure conditions; and means unloading both chambers as the motor is started.

15. In a pump control mechanism, the combination of a pump having a plurality of pumping. chambers; an electric motor driving the pump; an unloader for one chamber operating to unload and load its chamber in response to variations of fluid pressure conditions; means stopping the motor in response to other variations in fluid pressure conditions; and speed responsive mechanisms maintaining an unloaded condition as the pump is started.

16. In a pump control mechanism, the combination of a pump having a plurality of pumping chambers; an electric motor drivmg the pump; an unloader for one chamber operating to unload and load its chamber in response to variations of fluid pressure conditions; a starting switch having a starting and a running position at opposite sides of a neutral position; means responsive to other variations in fluid pressure conditions actuating said switch; and speed responsive mechanisms maintaining an unloaded condition as the pump is started.

17. In a pump control mechanism, the combination of a pump having a plurality of pumping chambers; an electric motor driving the pump; separate unloaders for the chambers operating in response to different pump controlled fluid pressure conditions, one unloading and loading its chamber with the motor in motion in response to variations in pressure conditions; means unloading both chambers as the motor is started; and speed responsive mechanisms maintaining an unloaded condition as the pump is started.

18. In a pump control mechanism, the combination of a pump having a plurality of pumping'chambers; an electric motor driving the pump; a starting switch for the motor having a starting and a running position at opposite sides of a neutral position; separate unloaders for the chambers operating in response to different pump controlled fluid pressure conditions, one unloader unloading and loading its chamber with the motor in motion in response to variations in fluid pressure conditions; means unloading both chambers as the motor is started; and speed responsive mechanisms maintaining an unloaded condition as the pump is started.

19. In a pump control mechanism, the combination of a pump having a plurality of pumping chambers; an electric motor drivmg the pump; a starting switch for the motor having a starting and a running position at opposite sides of a neutral position; separate unloaders for the chambers operating in response to different pump controlled fluid pressure conditions, one unloader unloading and loading its chamber with the motor in motion in response to variations in fluid pressure conditions; means operating on the switch stopping the motor in response to other variations and unloading both chambers as the motor is started;

and speed responsive mechanisms maintaining an unloaded, condition as the pump is started.

20. In a pump control mechanism, the combination of a pump; an electric motor driving the pump; a starting switch for the motor having a starting and a. running position at opposite sides of a neutral position; means acting on the switch controlling the motor comprising a fluid storage chamber replenished from the pump; and devices re-v sponding to fluid pressure conditions and actuated by the chamber pressure automatically actuating the switch to starting and running positions.

21. In a pump control mechanism, the combination of a pump; an electric motor driving the pump; a switch controlling the motor having a starting and a running position at opposite sides of a neutral position; means acting on the switch throwing the same to starting and running'position comprising a fluid storage chamber; devices charging the chamber as the switch is thrown to neutral position under certain fluid pres sure conditions; and mechanism actuated by the chamber fluid pressure moving the switch to start the motor under certain other fluid conditions.

22. In a pump control mechanism, the combination of a pump; an electric motor driving the pump; a. switch controlling the motor having a starting and a running position at opposite sides of a neutral position; a fluid actuated trip device for tripping the switch; means controlling the trip device and acting on the switch throwing it to starting and running position comprising a fluid storage chamber; control devices acting on the trip device to stop the motor and charge the chamber under certain fluid pressure conditions; and mechanism actuated by the chamber fluid pressure acting on the switch to throw it to starting and then to running position.

23. In a pump control mechanism, the

combination of a pump; an electric motor driving the pump; means controlling the motor comprisin a fluid storage chamber and fluid actuate devices connected with the chamber; control devices stopping the motor and charging the chamber with certain fluid pressure conditions; mechanism actuated by the chamber fluid pressure starting the motor with certain other fluid pressure conditions; and speed responsive mechanism controlling said devices.

24. In a pump control mechanism, the combination of a pump; an electric motor driving the pump; a switch controlling the motor having a starting and a running position at opposite sides of a neutral position; means acting on the switch throwing the same to starting and running position comprising a fluid storage chamber; devices charging the chamber as the switch is thrown to neutral position with certain fluid pres. sure conditions; mechanism actuated by the chamber fluid pressure moving the switch to start the motor under certain other fluid pressure conditions; and speed responsive mechanism cont-rolling said means.

25. In a pump control mechanism, the combination of a pump; an electric motor driving the pump; means controlling the motor comprising a fluid storage chamber replenished from the pump; devices responding to fluid pressure conditions and actuated by chamber pressure automatically starting the motor in response to fluid pressure conditions; an unloader; and devices actuating the unloader by chamber fluid pressure maintaining the pump in unloaded condition as the motor is started.

26. In a pump control mechanism, the combination .of a pump; an electric motor driving the pump; means controlling the motor comprising a fluid storage chamber; control devices stopping the motor and charging the chamber with certain fluid pressure conditions; mechanism actuated by the chamber fluid pressure starting the motor with certain other fluid pressure conditions; and an unloader for the pump actuated by chamber fluid pressure.

27. In a pump control mechanism, the combination of a pump; an electric motor driving the pump; means controlling the motor comprising a fluid storage chamber; control devices stopping the motor and charging the chamber with certain fluid pressure conditions; mechanism actuated by the chamber fluid pressure starting the motor with certain other fluid pressure conditions; an unloader; and devices actuating the unloader by chamber fluid pressure maintaining the pump in unloaded condition as the motor is started.

28. In a pump control mechanism, the combination of a pump; an electric motor driving the pump; means controlling the motor comprising a fluid storage chamber; control devices stopping the motor and charging the chamber with certain fluid pressure conditions; mechanism actuated by the chamber fluid pressure starting the motor with certain other fluid pressure conditions; speed responsive mechanism controlling said means; and an unloader for the pump actuated by chamber fluid pressure.

29. In a pump control mechanism, the combination of a pump having a plurality of pumping chambers; an electric motor drivmg said pump; means controlling the motor comprising a fluid storage chamber; control devices stopping the motor and charging the chamber with certain fluid pressure conditions; mechanism actuated by the chamber fluid pressure starting the motor with certain other fluid pressure conditions; and unloaders for each chamber, one of said unloaders being actuated by chamber pressure.

30. In a pump control mechanism, the combination of a pump having a plurality of pump'in chambers; an electric motor driving sai pump; means controlling the motor comprising a fluid storage chamber; control devices stopping .the, motor and charging the chamber with certain fluid pressure conditions; mechanism actuated by the chamber fluid pressure starting the motor with certain other fluid pressure conditions; and unloaders for each chamber, one of said unloaders being actuated by chamber pressure and the other unloader by fluid subjected directly to pump action.

31. In a pump control mechanism, the combination of a pump having a plurality of pumping chambers; an electric motor driving said pump; means controlling the motor comprising a fluid storage chamber; control devices stopping the motor and charging the chamber with certain fluid one of said unloaders being actuated by the chamber fluid pressure starting the motor with certain other fluid pressure conditions; and unloaders for each chamber, one of said unloaders being actuated by chamber pressure to maintain the pump in unloaded condition during the starting of the motor.

32. In a pump control mechanism, the combination of a pump having a plurality of pumping chambers; an electric motor driving said pump; means controlling the motor comprising a fluid storage chamber; control devices stopping" the motor and charging the chamber with certain fluid pressure conditions; mechanism actuated by the chamber fluid pressure starting the motor with certain other fluid pressure conditions; unloaders for each chamber, one of said unloaders being actuated by chamber pressure; and a speed responsive device controlling said starting mechanism.

33. In a pump control mechanism, the combination of a pump having a plurality of pumping chambers; an electric motor driving said pump; means controlling the motor comprising a fluid storage chamber; control devices stopping the motor and charging the chamber with certain fluid pressure conditions; mechanism actuated by the chamber fluid i pressure starting the motor with certain other fluid pressure conditions; unloaders for each chamber, one of said unloaders being actuated by chamber pressure to maintain the pump'in unloaded condition during the starting of the motor; and a speed responsive device controlling said starting mechanism.

34. In a pump control mechanism, the combination of a pump; an electric motor driving the pump; a receiver; a fluid storage chamber; a switch controlling the motor; a fluid actuated apparatus for actuating theswitch; a pilot valve sensitive to receiverpressure; and means controlled by the pilot valve releasing the switch and charging the chamber and connecting the chamber with the motor to throw the switch.

35. In a pump control mechanism, the combination of a pump;'an electric motor drivin the pump; a receiver; a fluid storage cliamber; a switch controlling the motor; a fluid actuated apparatus actuating the switch comprising a trip device releasing the switch to stop theinotor; a pilot valve sensitive to receiver pressure; and means controlled by the pilot valve releasing the switch and charging the chamber and connecting the chamber with the motor to throw the switch.

36. In a pump control mechanism, the combination of a pump; an electric motor driving the pump; a receiver; a fluid storage chamber; a switch controlling the motor; a fluid actuated apparatus actuating the switch; a pilot valve sensitive to receiver pressure; means controlled by the pilot valve releasing the switch and charging the chamber and connecting the chamber with the motor to throw the switch; and an auto matically actuated valve in the connection venting apparatus.

37. In a pump control mechanism, the combination of a pump; an electric motor driving the pump; a receiver; a fluid storage chamber; a starting switch for the motor having a starting and a running position at opposite sides'oi' a neutral position; a fluid actuated apparatus actuating the switch; a

pilot valve sensitive to receiver pressure; and means controlled by the pilot valve releasing the switch and charging the chamber and connecting the chamber with the apparatus to throw the switch to starting position.

38. In a pump control mechanism, the combination of a pump; an electric motor driving the pump; a receiver; a fluid storage and connecting the chamber with the apparatus to throw the switch to starting position; and devices connecting the chamber with the apparatus to throw the switch to running position.

39. In a. pump control mechanism, the

combination of a pump; an electric motor driving the pump; a receiver; a fluid storage chamber; a starting switch for the motor having a starting and a running position at opposite sides of a neutral position; a fluid actuated apparatus actuating the switch; a pilot valve sensitive to receiver pressure; means controlled by the pilot valve releasing the switch and charging the chamber and connecting the chamber with the apparatus to throw'the switch to starting position; and devices connecting the chamher with the apparatus to throw the switch to running position comprising a speed responsive device.

40. In a pump control mechanism, the combination of a pump; an electric motor driving the pump; a receiver; a fluid storage chamber; a switch controlling the motor; a fluid actuated apparatus for actuating the switch; a pilot valve sensitive to receiver pressure; means controlled by the pilot valve releasing the switch and charging the chamber and connecting the chamber with the motor to throw the switch; and an unloader actuated by the chamber pressure.

41. In a pump control mechanism, the

combination of a pump; an electric motor opposite sides of a neutral position; a fluid actuated apparatus actuating the switch; a

pilot valve sensitive to receiver pressure; means controlled by the pilot valve releasing the switch and charging the chamber and connecting the chamber with the apparatus to throw the switch to starting position; and an unloader actuated by chamber pressure.

42. In a pump control mechanism, the combination of a pump; an electric motor driving the pump; a receiver; a fluid storage chamber; a starting switch for the motor having a starting and a running position at opposite sides of a neutral position, a trip device releasing the switch to permit it to return to neutral osition; a fluid actuated apparatus actuating the switch; a pilot valve sensitive to receiver pressure; and means controlled by the pilot valve operating the trip to release the switch and I return to neutral charging the chamber and connecting the chamber with the apparatus to throw the switch.

43. In a pump control mechanism, the combination of a pump; an electric motor driving the pump; a receiver; a fluid storage chamber; a starting switch for the motor having a starting and a running position at opposite sides of a neutral position; a trip device releasing the switch to permit it to return to neutral position; a fluid actuated apparatus actuating the switch; a pilot valve sensitive to receiver pressure; means controlled by the pilot valve operating the trip to release the switch and charging the chamber and connecting the chamber with the apparatus to throw the switch to starting position; and means to connect the apparatus with the chamber to throw the switch to running position.

44. In a pump controlmechanism, the combination of a pump; an electric motor driving the pump; a receiver; a fluid storage chamber; a starting switch for the motor having a starting and a running position at opposite sides of a neutral position; a trip device releasing the switch to permit it to position; a fluid actuated apparatus actuating the switch; a pilot valve sensitive to receiver ressure; means controlled by the pilot va ve' operating the trip to release the switch and charging the chamber andconnecting the chamber with the apparatus to throw the switch; and an unloader actuated by the chamber pressure.

45. In a pump controlling mechanism, the combination of a pump; a storage chamber receiving pressure from the pump; a pilot valve controlling the storage chamber; an electric switch; an apparatus controlling the switch; a motor operating the apparatus actuated by storage chamber pressure; a valve connecting the chamber and apparatus, a motor actuating the switch; and means connecting the motor with the storage chamber to move the switch to a starting position comprising a pressure actuated starting valve controlled by the pilot valve.

46. In a pump controlling mechanism, the combination of a pump; a storage chamber receiving pressure from the pump; a pilot valve controlling the storage chamber; an electric switch; an apparatus controlling the switch; a motor operating the apparatus actuated by storage chamber pressure; a valve connecting the chamber and apparatus; a. motor actuating the switch; means" connecting the motor with the storage chamher to move the switch to a starting position comprising a pressure actuated starting valve controlled by the pilot valve; and a vent valve in the connection between the starting valve and the motor.

47. In a pump controlling mechanism, the combination of a pump; a storage chamber receiving pressure from the pump; a pilot valve controlling the storage chamber; an electric switch; an apparatus controlling the switch; a motor operating the apparatus actuated by storage chamber pressure; a valve connecting the chamber and apparatus; a motor actuating the switch; and means connecting the motor with the storage chamber to move the switch to a starting position comprising a fluid actuated starting valve controlled by the pilot valve and having a vent passage for venting the connection with the closing of the starting valve.

48. In a pump control mechanism, the combination of a pump; a pilot valve sensitive to pumped fluid; a pressure storage chamber receiving fluid from the pump and controlled by the pilot valve; an electric switch having a starting and a running position at opposite sides of a neutral position; a motor controlling the switch; a running condition connection between the store e chamher and the motor; a valve control ing said connection; and means controlling the valve.

49. In a pump control mechanism, the combination of a pump; a pilot valve sensitive to pumped fluid; a pressure storage chamber receiving fluid from the pump and controlled by the pilot valve; an electric switch having a startin and a running position at opposite sides 0 a neutral position; a motor controlling the switch; a running condition connection between the storage chamber and the'motor; a valve controlling said connection; and means controlling the valve comprising a speed sensitive device.

50. In a pump control mechanism, the

combination of a pump; a pilot valve sensitive to pumped fluid; a pressure storage chamber receiving fluid from the pump and controlled by the pilot valve; an electric switch having a startin and a running position at opposite sides 0 a neutral position; a motor controlling the switch; a running condition connection between the storage chamher and the motor; a valve controlling said connection; means controlling the valve; an

a vent valve in the connection.

51. In a pump control mechanism, the combination of a switch having a starting and a running position at opposite sides of a neutral position; a motor actuating said switch; a pressure chamber; a starting connection between the pressure chamber and the motor; a running connection between the pressure chamber and the motor; and means controlled by fluid pressure conditions controlling said connections.

52. In a pump control mechanism, the combination of'a switch having a starting and a running position at opposite sides of a neutral position; a motor actuating said switch; a pressure chamber; a starting connection between the pressure chamber and the motor; a running connection between the pressure chamber and the motor; and means controlled by fluid pressure conditions controlling said connections comprising a valve in the running position connection and a speed sensitive device controlling said valve.

:33. In a pump control mechanism, the combination of a switch having a starting and a running position at opposite sides of a neutral position; a motor actt'ating said switch; a pressure chamber; a starting connection between the pressure chamber and the motor; a running connection between the pressure chamber and the motor; means controlled by fluid pressure-conditions controllin the starting connection; and means controlled by speed conditions controlling the running connection.

54. In a pump control mechanism, the combination of an electric switch having a startin and a running position at opposite sides. Ia neutral position; a trip device for tripping the switch to permit it to move from the running position to neutral position; a motor throwing said switch to starting and running positlon; a pressure chamber; a starting connection between'the pressure chamber and the motor; a running connection between the pressure chamber and the motor; pressure controlled devices controlling the trip device andstarting connection; and a speed controlled device controlling the running connection.

55. In a pump control mechanism, the combination of a switch having a starting and a running osition at opposite sides of a neutral posit1on;'a motor actuating said switch; a pressure chamber; a starting connection between the pressure chamber and the motor; a running connection between the pressure chamber and the motor; means controlled by fluid conditions controlling said connections; and an unloader responsive to pressure conditions in said connections.

56. In a pump control mechanism, the combination of an electric switch having a starting and a running position at opposite sides of a neutral position; a trip device for tripping the switch to permit it to move from the running position to neutral position; a motor throwing said switch to starting and running position; a pressure chamber; a starting connectioubetw een the pres sure chamber and the motor; a running connection between the pressure chamber and the motor; pressure controlled devices con trolling the trip device and starting connection; a speed controlled device controlling.

the running connection; and an unloader responsive to conditions in said connections.

57. In a pump control mechanism, the combination of an electric switch having a starting and a running position at opposite sides of a neutral position; a trip device for tripping the switch to permit it to move from the running position to neutral position; a motor throwing said switch to starting and running position; a.- pressure chamber; a starting connection between the pressure chamber and the motor; a running connection between the pressure chamber and the motor; pressure controlled devices controlling the trip device and starting connection; a speed controlled device controlling the running connection; and an unloader responsive to conditions in said connections to maintain the unloader in unloaded position as the switch is thrown to starting position.

58. In a pump control mechanism, the combination of a switch having a starting and a running position at opposite sides or a neutral position; a motor actuating said .switch; a storage pressure chamber; a starting connection between the pressure storage chamber and the motor; a running connection between the storage pressure chamber and the motor; a receiver; a connection between the receiver and the storage chamber; and means controlled by receiver pressure controlling the connection between the receiver and the storage chamber and the starting connection;

59. In a pump control mechanism, the combination of an electric switch having a starting and a running position at opposite sides of a neutral position; a trip device for tripping the switch to permit it to move from the running position to-neutral position; a motor throwing said switch to starting and running position; a storage pressure chamber; a starting connection between the storage pressure chamber and the motor; a running connection between the storage pressure chamber and the motor; a receiver; a connection between the receiver and the storage pressure chamber; and a pressure actuated device controlling the connection betweenthe receiver and the storage chamber and the trip device and the starting con-, nection.

60. In a pump control mechanism, the combination of a switch having a starting and a running position at opposite sides of a neutral position; a motor actuating said switch; a storage pressure chamber; a starting connection between the pressure storage chamber and the motor; a running connection between the storage pressure chamber and the motor; a receiver; a connection be tween the receiver and the storage chamber; means controlled by receiver pressure controlling the connection between the receiver and the storage chamber and the starting connection; and an unloader actuated by the storage chamber pressure.

(51.111 a pump control -mechan-ism, the combination of an electric switch having a starting and a running position at opposite sides of a neutral position; a trip device for tripping the switch to permit it to move from the running position to neutral position; a motor throwing said switchto starting and running position; a storage pressure chamber; a starting connection between the storage pressure chamber and the motor; a running connection between the storage pressure chamber and the motor; a receiver; a connection between the receiver and the storage pressure chamber; a pressure actuated device controlling the connection between the receiver and the storage chamber and the trip device and the starting connection; a speed sensitive device controlling the running connection; and an unloader actuated by the storage chamber pressure.

(3'2. In a pump control mechanism, the combination of a receiver; an auxiliary storage pressure chamber receiving its supply from the receiver; an electric starting switch mounted on the storage pressure chamber; and means actuated by pressure from the chamber for actuating the switch.

(325. In a pump control mechanism, the' combination of a pump; analternating electric motor actuatlng the pump; an alternating motor starting switch having a starting and a running position; and fluid actuated means responsive to conditions of fluid pressuresubjected to the action of the pump actuating the switch.

(34. In a pump control mechanism, the

, combination of a pump; an alternating electric motor actuating the pump; an alternating motor starting switch having a starting and a running position; and means actuated by the pumped fluid actuating the switch. I

($5. In a pump control mechanism, the combination 'of a pump; an alternating electric motor actuating the pump; an alternating motor starting switch comprising actuating mechanism having a starting and a running position; fluid actuated means responsive to conditions of fluid pressure subjected to the action of the pump actuating the switch mechanism; and a speed responsive device controlling the timing of the transfer of the switch mechanism from starting to running position.

(56.111 a pump control mechanism, the combination of a pump; an alternating electric motor actuating the pump; an alternating motor starting switch comprising actuating mechanism having a starting and a running position; means actuated by the pumped fluid actuating the snitch mechanism; and a speed responsive device con trolling the timing of the transter of the switch mechanism from starting to running position.

67. ln a pump control mechanism, the combination of a pump; an alternating electric motor actuating the pump; an alternating motor starting switch having a starting and a running position; fluid actuated means responsive to conditions of fluid pressure subjected to the action of the pump actuating the switch adapted to automatically start and stop the motor in response to fluid conditions; an unloader;

and mechanisnrcoacting with said means maintaining the unloader in unloading position as the motor is started.

(38. In a pump control mechanism, the comhination of a pump; an alternating electric motor actuating the pump; an alternating motor starting switch comprising actuating mechanism having a starting and a runnin position; means actuated by the pumped fluid actuating the switch mechanism; a speed responsive device controlling the timing of the transfer of the switch mechanism from starting to running position; an unloader; and mechanism coacting with said means and device for maintaining the unloader in unloading position as the motor starts.

(39. In a pump control mechanism, the combination of a pump having a plurality of pumping units; an alternating electric motor actuating the pump; an unloader for one unit operating to unload and load its unit in response to variations of fluid pressure conditions; an alternating motor starting switch having a starting and a running position; and means responsive to other variations in fluid pressure conditions automatically actuating said switch to start and stop the motor.

70. In a pump control mechanism, the combination of an alternating electric motor; a source of fluid supply under pressure; an alternating starting motor switch having a starting and a running position controlling the motor; and fluid pressure means actuating the switch.

71. In a pump control mechanisnn the combination of an alternating electric motor; a source of fluid supply under pressure; an alternating starting motor switch having a starting and a running position controlling the motor; and fluid pressure means actuating the switch comprising a storage chamber replenished from the source of supply.

72.111 a pump control mechanism, the combination of an alternating electric motor; a source ot fluid supply under pressure; an alternating starting motor switch having a starting and a running position controlling the motor; fluid pressure means actuating the switch; and speed responsive mechanism controlling the movement of the switch from starting to running position.

73. In a pump control mechanism, the combination of an alternating electric motor; an alternating motor starting switch having a starting and a running position controlling said motor; a source of fluid supply; a storage chamber replenished from said source of suppl fluid actuated devices controlling the motor connected with said storring position; a fluid actuated apparatus acage chamber; and a speed responsive device tuating the switch; a pilot valve sensitive controlling said fluid actuated devices to to receiver pressure; and means controllel throw the switch from starting to running by the pilot valve releasing the switch and 0 position. charging the chamber and connecting the T4. In a pump control mechanism, the chamber with the apparatus to throw the combination of a pnmp; an alternating elecswitch to starting position. tric motor driving the pump; a receiver; a In testimony whereofl have hereunto set 1 fluid storage chamber; an alternating motor my hand.

RUDOLPH CONRADER.

10 starting switch having a starting and a run- 

